Costatisporus cyanescens is a sequestrate fungal species known exclusively from its description in 2015 based on collections made in 2 sites in Guyana. The lack of any more records may be a result of undersampling so it is not possible to determine if this species has a restricted distribution or small population. Further research and search efforts are needed so C. cyanescens is assessed as Data Deficient (DD).

Type and only species in the Costatisporus, established by Smith et al. in 2015, based on morphological and molecular data.

Known from 2 sites in the Upper Potaro River Basin of Guyana in South America.

Further records or search efforts are needed to establish population size and distribution.

C. cyanescens has hypogeous to partially emergent, solitary to scattered fruitbodies. It was found growing on mineral soil or in the humic layer under the ectomycorrhizal trees Dicymbe corymbosa or Aldina insignis, in closed canopy tropical wet rainforest. (Smith et al., 2015).

Without further research into habitat preferences it is difficult to establish threats for this species. Neither Dicymbe corymbosa or Aldina insignis, two potential hosts, have been assessed by the IUCN Red List of Threatened Species.

Targeted search efforts and research into the ecology are needed to establish potential host preferences and determine population size and distribution for this species.